Oven complex made of burnt clay and destroyed tile fragments dated from the second half of the 16th century to the 17th century was discovered behind the defensive wall (built in the years 1504-12 and completed around 1549) of the Lubranski Academy in Poznan. Cluster of yellow and olive-yellow clay (2.5Y 7/6, 7/8 and 5Y 6/6, 6/8 after Munsell 1973) and burnt clay (2.5YR 6/8, 5/8; 5YR 6/8) of c. 1 square m was found about 1 m away from the wali bricky-stony foundation (tile fragments and a lump of bumt clay were also found in a rubble layer III). Altogether 164 tile fragments were discovered: 46 fragments of plain tiles (22 with glazed face and 24 with unglazed face), 15 fragments of ridge tiles and/or frieze tiles (including 6 with glazed face), 36 fragments of tile body and 51 fragments of body edges (including 5 with glazed face). Having collected fragments of central plain tiles (along with the edge ones?), central ridge and possibly frieze (?) tiles, but without decorative elements (listels and pinnacles), it proved possible to make a hypothetical reconstruction of the oven. It was inspired by the so-called clove oven from the brick residence at Nowe Miasto (the first half of the 17th century), in particular as regards its proportion, constructional solutions, and stylistics. It is especially justified as the discussed rubble behind the wali contained numerous fragments of clove and acanthus tiles as well as similar fragments of an eagle with the crown coat of arms. Hence, it may have been a 'green' oven with the lower box placed directly on the continuous ridge. This box was possibly made of clove tiles with tight green glazed face, while the upper one was made of tiles with the 'plant' green and light green glazed inlay as well as the 'bricky' unglazed tiles with plant, plant with eagle motifs, and heraldic tile(s). More massive specimens (with 'thicker' body) were set to make the lower box supporting the lighter ones with shallower chambers making up the oven's upper part. The centrally placed ridge dividing both boxes might have been made of the 'ribbed' light green tiles. The upper edge of the oven might have been made of a reversibly placed ridge with geometric inlay (glazed or unglazed). Unfortunately, size of the oven, along with a number of tiles used for its construction as well as its original location cannot be reconstructed (the Lubranski Academy or neighbouring canonry). We cannot be sure that all elements originate from one oven (as we have to remember that complete tiles were often reused in new ovens), however this was certainly not an ordinary object (as indicated by tile fragment with an eagle with the crown). The green oven might have been dismantled in the second half of the 16th / 17th century. It is implied by e.g. historical sources from the end of the 16th century referring to the then deteriorating Lubranski Collegium, composed of six heated rooms requiring immediate renovationOne has also to remember that ovens at that time were used for c. 30-40 years. Broken and smoked fragments of tiles, bumt clay, smoked oven roof tiles as well as constructional rubble that were dumped behind the Lubranski wall were set to strengthen the wet and often flooded northern part of Ostrów Tumski.